EP0334583A2 - Pulp washer - Google Patents

Pulp washer Download PDF

Info

Publication number
EP0334583A2
EP0334583A2 EP89302748A EP89302748A EP0334583A2 EP 0334583 A2 EP0334583 A2 EP 0334583A2 EP 89302748 A EP89302748 A EP 89302748A EP 89302748 A EP89302748 A EP 89302748A EP 0334583 A2 EP0334583 A2 EP 0334583A2
Authority
EP
European Patent Office
Prior art keywords
pulp
baffle
drum
chamber
vat
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Granted
Application number
EP89302748A
Other languages
German (de)
French (fr)
Other versions
EP0334583A3 (en
EP0334583B1 (en
Inventor
Oscar Luthi
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Ingersoll Rand Co
Original Assignee
Ingersoll Rand Co
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Ingersoll Rand Co filed Critical Ingersoll Rand Co
Priority to AT89302748T priority Critical patent/ATE86689T1/en
Publication of EP0334583A2 publication Critical patent/EP0334583A2/en
Publication of EP0334583A3 publication Critical patent/EP0334583A3/en
Application granted granted Critical
Publication of EP0334583B1 publication Critical patent/EP0334583B1/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

Links

Images

Classifications

    • DTEXTILES; PAPER
    • D21PAPER-MAKING; PRODUCTION OF CELLULOSE
    • D21CPRODUCTION OF CELLULOSE BY REMOVING NON-CELLULOSE SUBSTANCES FROM CELLULOSE-CONTAINING MATERIALS; REGENERATION OF PULPING LIQUORS; APPARATUS THEREFOR
    • D21C9/00After-treatment of cellulose pulp, e.g. of wood pulp, or cotton linters ; Treatment of dilute or dewatered pulp or process improvement taking place after obtaining the raw cellulosic material and not provided for elsewhere
    • D21C9/02Washing ; Displacing cooking or pulp-treating liquors contained in the pulp by fluids, e.g. wash water or other pulp-treating agents
    • D21C9/06Washing ; Displacing cooking or pulp-treating liquors contained in the pulp by fluids, e.g. wash water or other pulp-treating agents in filters ; Washing of concentrated pulp, e.g. pulp mats, on filtering surfaces

Definitions

  • This invention relates to pulp washers. More particularivelyly, this invention is a new pulp washer and pulp washing method which is used to provide a pulp slurry output having the desired consistency.
  • the cooked pulp from the digesters is filtered and washed with water to remove the black liquid that would conta­minate the end product made from pulp and to recover the maximum amount of spent cooking chemicals with minimum dilution.
  • Most of the pulp washing today is done in vacuum washers.
  • a disadvantage of currently used vacuum washers of this type is that liquor extraction by air is undesirable in many processes because of foaming and chemical reactions.
  • This invention is a pulp washer and pulp washing method which is an improvement of the "Pulp Washer Discharging a Low Consistency Pulp Slurry" described in U.S. Patent No. 4,217,170.
  • this invention is a pulp washer having a rotatable drum, an air-tight vat completely enclosing the rotatable drum.
  • the vat is constructed so that the rotatable drum may be completely submerged in liquid so that the liquid surrounds the entire circumference of the drum.
  • the vat has a liquid filled take-off chamber.
  • the vat also has a pulp inlet with means directly following the pulp inlet for forming and compacting the pulp to form a pulp mat.
  • the forming and compacting is followed by means for washing the pulp mat. After the washing, means are provided to again compact the pulp mat. This is followed by means for removing the pulp mat from the drum.
  • the removal point is located in the liquid filled take-off chamber to provide a pulp suspension in said chamber.
  • the pulp suspension is removed from the vat through a pulp outlet extending from the liquid filled take-off chamber.
  • an air-tight vat 10 completely encloses a rotatable drum 12 which rotates in the vat 10.
  • the rotatable drum has its lower section submerged in the pulp slurry which is introduced into the pulp slurry chamber 13 by means of pulp slurry inlet 14.
  • a pulp mat 16 is formed on the drum.
  • This pulp mat may be compacted with a hydrodynamic baffle 18, serving as the primary baffle.
  • the primary baffle 18 is mounted downstream from the pulp slurry inlet 14 and applied a compacting force against the mat being formed. The force is applied by means of actuators 20, one shown in Fig. 1.
  • the hydrodynamic baffle 18 is preferably of a type that will compact the mat to a high consistency of say, 15% to 18% before entering the wash zone.
  • the com­pacted pulp mat 16 is washed by the application of a dif­ferential pressure across the circumferential wall of the rotatable drum 12 and the mat removed from the drum in the take-off chamber 32.
  • the air-tight vat 10 completely encloses the rotatable drum 12.
  • the vat is constructed so that the rotatable drum is completely submerged in liquid so that the liquid surrounds the entire circumference of the drum.
  • the wash zone 22 extends from the downstream end of the primary compaction baffle 18 to the downstream end of the secondary compaction baffle 24.
  • the wash zone 22 extends for more than 180° around the rotatable drum 12.
  • the primary compaction baffle 18 is pivotably connected at its upstream end to the vat by means of pivot 26.
  • the primary compaction baffle converges gradually inwardly toward the outside surface of the rotatable drum 12 from its upstream end to its downstream end to cause the com­paction of the pulp slurry into the mat 16.
  • Wash liquid enters the vat 10 through wash liquid inlet 28 and also aids the actuators 20 in the application of the compac­tion force against the mat.
  • An excluder baffle 30 interconnects the primary compac­tion baffle 18 and the secondary compaction baffle 24.
  • the excluder baffle extends partially along the wash zone 22 from the compaction zone to the secondary compaction baffle 24 which extends partially along the wash zone 22 and into the liquid filled take-off chamber 32.
  • the excluder baffle 30 diverges slightly from its up­stream end to its downstream end.
  • the excluder baffle may be coaxial or even converge slightly from its upstream end to its downstream end.
  • the excluder baffle 30 slidably engages the primary com­paction baffle 18.
  • the primary compaction baffle 18 has a slidable guide 34 at its downstream end which slidably engages the spaced apart posts 36 and 38 on the upstream end of the excluder baffle 30.
  • the secondary compaction baffle 24 and the excluder baffle 30 are pivoted from the same pivot point 40.
  • washing liquid entering the first wash liquid inlet 28 will completely fill the vat. There­after, during operation washing liquid entering the first wash liquid inlet 28 flows along the outside of the pri­mary compaction baffle 18.
  • the space 42 between the downstream end of the primary compaction baffle 18 and upstream end of the excluder baffle 30 is provided so that the washing liquid also flows along the inside sur­ face of coaxial baffle 30.
  • the wash liquid thereafter flows along the inside surface of the secondary compac­tion baffle 24.
  • a second washing liquid inlet 44 is circumferentially located at the excluder baffle 30 - secondary compaction baffle 24 connection.
  • the liquid fed through the second washing inlet 44 flows along the inside surface of the converging secondary compaction baffle 24.
  • the second washing liquid may be at a different temperature or con­centration than the liquid fed through the wash liquid inlet 28.
  • Actuators 46 (one shown in Fig. 1) apply a compaction force against the mat 16.
  • the various zones: forming and compaction zones, wash zone and take-off zone, are preferably all at the same pressure. Thus, any seals need only be used to separate the liquids. Seals do not have to seal against a pres­sure differential. A close clearance gap is sufficient.
  • the cylinder utilization is greatly increased when com­pared with other pulp washers.
  • the active cylinder arc is approximately 330°; only 30° of arc is needed for mat take-off and cylinder cleaning.
  • the downstream end of secondary compaction baffle 24 is shaped so that there is a close clearance gap between the downstream end 50 of the secondary compaction baffle 24 and the outside sur­face of the drum 12.
  • the downstream end of the secondary compaction baffle 24 is also shaped so that its surface 52 remains in sliding contact with a side of a flat plate 53 mounted on the vat 10.
  • pulp fibers will fall off the pulp mat 16 in the wash zone. With prior art washers, these pulp fibers float to the top of the vat and accumulate there. In time, a heavy wad may build up and plug the machine.
  • the excluder baffle confines the fibers which have fallen off the mat to a small space and the washing action causes the pulp fibers to redeposit on the pulp mat.
  • baffles Almost the whole circumference of the cylinder is sur­rounded by some kind of baffle. This leaves very little room for pulp to build up to a heavy wad and plug the machine. With both baffles in the open position, there is a divergent gap all around the cylinder to clear out any pulp.
  • the pulp mat 16 is again compacted by the secondary com­paction baffle to 12% to 15% consistency and then enters the take-off chamber 32.
  • a take-off roll 54 assists in removing the pulp mat from the drum.
  • the take-off roll 54 serves two functions: remove the pulp mat from the drum and convey the pulp longitudinally to the pulp outlet.
  • the take-off roll shown in Fig. 4 includes a plurality of flutes 56 which are preferably arranged in a spiral pattern.
  • a pressure zone 58 and suction zone 60 are created in the incoming and outgoing nip, respectively. This pressure and suction action will lift off the pulp mat from the cylinder.
  • the lifted-off pulp mat is conveyed longitu­dinally by the spirally arranged flutes 56 in the take-­off roller 54.
  • the conveying of the pulp suspension is also assisted by a pressure drop in the take-off chamber 32 towards the throttle valve 62 in pulp outlet 61 (see Fig. 1).
  • a dilution liquid inlet 64 is provided at the opposite longitudinal end of the take-off chamber 32 from the pulp outlet 61 for feeding dilution liquid into the take-off chamber 32.
  • the consistency of the pulp in take-off chamber 32 may be adjusted over a wide range by feeding a predetermined amount of dilution liquid into the take-off chamber 32 by means of the dilution liquid inlet 64.
  • a doctor 66 Underneath the take-off roll 54 is a doctor 66 which can be operated with steam or water or with a combination of steam and water fed through manifold 67, port 69, and slot 71. The doctor removes any remaining crumbs of pulp and cleans the drum for the next cycle.
  • the pulp is fed to the vat 10 through pulp inlet 14.
  • the pulp is formed and compacted into a pulp mat 16 by the first compaction baffle 18.
  • the secondary compaction baffle 24 converges to­ward the drum from its upstream end to the downstream end to again compact the mat 16.
  • the take-off roll 54 removes the mat from the drum 12 and the pulp thus removed is longitudin­ally conveyed through the flutes of the take-off roll 54 to the pulp outlet 62.
  • the consistency of the pulp from the pulp outlet 62 may be controlled by feeding dilution liquid into the take-off chamber 32 through dilution liquid inlet 64.
  • a longitudinally extending pivot 80 extends through a plurality of longitudinally separated pairs of brackets 82 and 84 (only one pair shown in the Fig. 2). Brackets 82 are connected to the downstream end of excluder baffle 30; brackets 84 are connected to the upstream end of the secondary compaction baffle 24.
  • the operation of the pulp washer of Fig. 2 is similar to the operation of the pulp washer of Fig. 1.
  • Pulp enter­ing inlet 14 is compacted in the compaction zone by the primary compaction baffle 18 to form the mat 16.
  • the mat 16 thereafter flows under the excluder baffle 30 and un­der the secondary compaction baffle 24 as it is washed in the wash zone of the drum.
  • the secondary compaction baf­fle 24 again compacts the mat 16.
  • the take-off cham­ber 32 the mat is removed from the drum by the take-off roll 54 and longitudinally conveyed along the flutes of the take-off roll 54 to the pulp outlet 61 controlled by throttle valve 62.
  • the consistency of the pulp from the take-off chamber 32 may be controlled by adding dilution liquid into the take-off chamber 32 through dilution liquid 64.
  • the first washing liquid inlet 90 extends into the vat 10 by means of a metal tube 92 having a portion 93 turned to extend toward the down­stream end of the vat.
  • Metal portion 93 extends into one end of a rubber sleeve 94 which in turn surrounds the end of a tubular member 96 which is attached to a bracket 98 connected to the first compaction baffle 18.
  • the bracket 98 is provided with an opening 100 through which the washing liquid entering the washing inlet 90 flows.
  • the washing liquid then flows along the inside surface of the excluder baffle 30 and along the inside surface of the secondary compaction baffle 24.
  • the downstream end of the primary compaction baffle 18 is pivotably connected to the upstream end of the excluder baffle 30 by means of a pivot pin 102 extending through bracket 104.
  • An actuator 106 applies a compaction force against the excluder baffle 30.
  • Piston rod 108 extends from actuator 106 to the generally radially extending member 110.
  • An arm 112 having a slot 114 is connected to the member 110 by pin 116.
  • Bracket 118, connected to the excluder baf­fle 30 has a peg 120 which fits within slot 114 in the arm 112.
  • the arm 112 is pivoted to vat 10 by pivot pin 122.
  • a second washing liquid inlet 123 extends into the vat 10 upstream from the first washing inlet 90. Liquid enter­ing the wash liquid inlet 123 flows along the outside of primary compaction baffle 18, then along the outside of the excluder baffle 30, and then along the inside of the secondary compaction baffle 24.
  • the secondary compaction baffle 24 is provided at its upstream end with a bracket 124 which is pivotably connected by pivot pin 125 to bracket 126 extending from the wall of vat 10.
  • the second washing liquid may be at a different temperature or concentration from the washing liquid fed through washing liquid inlet 90. Also, even though two washing liquid inlets are shown, more than two washing liquid inlets may be provided, if desired.
  • pulp enter­ing inlet 14 is compacted in the compaction zone by the primary compaction baffle 18 to form the mat 16.
  • the mat 16 thereafter flows under the excluder baffle 30 and un­der the secondary compaction baffle 24 as it is washed in the wash zone of the drum.
  • the secondary compaction baf­fle 24 again compacts the mat 16.
  • the take-off cham­ber 32 the mat is removed from the drum by the take-off roll 54 and longitudinally conveyed along the flutes of the take-off roll 54 to the pulp outlet 61 controlled by throttle valve 62.
  • the consistency of the pulp in the take-off chamber 32 may be controlled by adding dilution liquid into the take-off chamber 32 through dilution liquid inlet 64.

Landscapes

  • Life Sciences & Earth Sciences (AREA)
  • Engineering & Computer Science (AREA)
  • Wood Science & Technology (AREA)
  • Paper (AREA)
  • Cleaning Implements For Floors, Carpets, Furniture, Walls, And The Like (AREA)
  • Glass Compositions (AREA)
  • Saccharide Compounds (AREA)
  • Beans For Foods Or Fodder (AREA)
  • Spinning Methods And Devices For Manufacturing Artificial Fibers (AREA)
  • Commercial Cooking Devices (AREA)

Abstract

An air-tight vat (10) under pressure completely encloses a rotatable drum (12). The vat (10) is constructed so that it may be completely submerged in liquid. The vat has a liquid filled take-off chamber (32). The pulp is fed to the vat through a pulp inlet (14). The pulp is formed and compacted to form a pulp mat. Directly following the forming and compacting of the pulp is a washing zone for washing the pulp mat. After washing the pulp mat is again compacted. The pulp mat is removed from the drum at a removal point located in the liquid filled take-off chamber, thus providing a pulp suspension in the take-off chamber. The suspension is removed from the vat through a pulp outlet (61) extending from the liquid filled take-off chamber (32).

Description

  • This invention relates to pulp washers. More particular­ly, this invention is a new pulp washer and pulp washing method which is used to provide a pulp slurry output having the desired consistency.
  • The cooked pulp from the digesters is filtered and washed with water to remove the black liquid that would conta­minate the end product made from pulp and to recover the maximum amount of spent cooking chemicals with minimum dilution. Most of the pulp washing today is done in vacuum washers. A disadvantage of currently used vacuum washers of this type is that liquor extraction by air is undesirable in many processes because of foaming and chemical reactions.
  • The pulp washer described in U.S. Patent No. 4,217,170 issued August 12, 1980 and entitled "Pulp Washer Dis­charging a Low Consistency Pulp Slurry" in the name of Oscar Luthi describes a pulp washer which is substanti­ally air-tight and completely encloses a rotatable cylin­der on which the pulp mat is formed. Therefore, the air is eliminated and the undesirable effects of liquor ex­traction by air such as foaming and undesirable chemical reactions are no longer present in the vat. The pulp washer described in U.S. patent No. 4.217,170 has as an output a low consistency pulp slurry output.
  • This invention is a pulp washer and pulp washing method which is an improvement of the "Pulp Washer Discharging a Low Consistency Pulp Slurry" described in U.S. Patent No. 4,217,170.
  • Briefly described, this invention is a pulp washer having a rotatable drum, an air-tight vat completely enclosing the rotatable drum. The vat is constructed so that the rotatable drum may be completely submerged in liquid so that the liquid surrounds the entire circumference of the drum. The vat has a liquid filled take-off chamber. The vat also has a pulp inlet with means directly following the pulp inlet for forming and compacting the pulp to form a pulp mat. The forming and compacting is followed by means for washing the pulp mat. After the washing, means are provided to again compact the pulp mat. This is followed by means for removing the pulp mat from the drum. The removal point is located in the liquid filled take-off chamber to provide a pulp suspension in said chamber. The pulp suspension is removed from the vat through a pulp outlet extending from the liquid filled take-off chamber.
  • The invention as well as its many advantages may be fur­ther understood by reference to the following detailed description and drawings in which:
    • Fig. 1 is a front sectional view showing one embodi­ment of the invention;
    • Fig. 2 is a front sectional view showing a second em­bodiment of the invention;
    • Fig. 3 is a front sectional view showing a third embodiment of the invention; and
    • Fig. 4 is a fragmentary view on an enlarged scale il­lustrating the operation of the take-off roll and steam or water doctor of the embodiments of Fig. 2 and Fig. 3.
  • In the various figures, like parts are referred to by like numbers.
  • Referring to the drawings and more particularly to Fig. 1, an air-tight vat 10 completely encloses a rotatable drum 12 which rotates in the vat 10. The rotatable drum has its lower section submerged in the pulp slurry which is introduced into the pulp slurry chamber 13 by means of pulp slurry inlet 14.
  • As the drum rotates, a pulp mat 16 is formed on the drum. This pulp mat may be compacted with a hydrodynamic baffle 18, serving as the primary baffle. The primary baffle 18 is mounted downstream from the pulp slurry inlet 14 and applied a compacting force against the mat being formed. The force is applied by means of actuators 20, one shown in Fig. 1. The hydrodynamic baffle 18 is preferably of a type that will compact the mat to a high consistency of say, 15% to 18% before entering the wash zone. During the remaining portion of the drum turning cycle, the com­pacted pulp mat 16 is washed by the application of a dif­ferential pressure across the circumferential wall of the rotatable drum 12 and the mat removed from the drum in the take-off chamber 32.
  • The air-tight vat 10 completely encloses the rotatable drum 12. The vat is constructed so that the rotatable drum is completely submerged in liquid so that the liquid surrounds the entire circumference of the drum.
  • The wash zone 22 extends from the downstream end of the primary compaction baffle 18 to the downstream end of the secondary compaction baffle 24. The wash zone 22 extends for more than 180° around the rotatable drum 12.
  • The primary compaction baffle 18 is pivotably connected at its upstream end to the vat by means of pivot 26. The primary compaction baffle converges gradually inwardly toward the outside surface of the rotatable drum 12 from its upstream end to its downstream end to cause the com­paction of the pulp slurry into the mat 16. Wash liquid enters the vat 10 through wash liquid inlet 28 and also aids the actuators 20 in the application of the compac­tion force against the mat.
  • An excluder baffle 30 interconnects the primary compac­tion baffle 18 and the secondary compaction baffle 24. The excluder baffle extends partially along the wash zone 22 from the compaction zone to the secondary compaction baffle 24 which extends partially along the wash zone 22 and into the liquid filled take-off chamber 32. In Fig. 1, the excluder baffle 30 diverges slightly from its up­stream end to its downstream end. However, for certain types of pulp, the excluder baffle may be coaxial or even converge slightly from its upstream end to its downstream end.
  • The excluder baffle 30 slidably engages the primary com­paction baffle 18. The primary compaction baffle 18 has a slidable guide 34 at its downstream end which slidably engages the spaced apart posts 36 and 38 on the upstream end of the excluder baffle 30. The secondary compaction baffle 24 and the excluder baffle 30 are pivoted from the same pivot point 40.
  • At start-up, washing liquid entering the first wash liquid inlet 28 will completely fill the vat. There­after, during operation washing liquid entering the first wash liquid inlet 28 flows along the outside of the pri­mary compaction baffle 18. The space 42 between the downstream end of the primary compaction baffle 18 and upstream end of the excluder baffle 30 is provided so that the washing liquid also flows along the inside sur­ face of coaxial baffle 30. The wash liquid thereafter flows along the inside surface of the secondary compac­tion baffle 24.
  • A second washing liquid inlet 44 is circumferentially located at the excluder baffle 30 - secondary compaction baffle 24 connection. The liquid fed through the second washing inlet 44 flows along the inside surface of the converging secondary compaction baffle 24. The second washing liquid may be at a different temperature or con­centration than the liquid fed through the wash liquid inlet 28.
  • Actuators 46 (one shown in Fig. 1) apply a compaction force against the mat 16.
  • The various zones: forming and compaction zones, wash zone and take-off zone, are preferably all at the same pressure. Thus, any seals need only be used to separate the liquids. Seals do not have to seal against a pres­sure differential. A close clearance gap is sufficient. The cylinder utilization is greatly increased when com­pared with other pulp washers. The active cylinder arc is approximately 330°; only 30° of arc is needed for mat take-off and cylinder cleaning. The downstream end of secondary compaction baffle 24 is shaped so that there is a close clearance gap between the downstream end 50 of the secondary compaction baffle 24 and the outside sur­face of the drum 12. The downstream end of the secondary compaction baffle 24 is also shaped so that its surface 52 remains in sliding contact with a side of a flat plate 53 mounted on the vat 10.
  • Usually, some of the pulp fibers will fall off the pulp mat 16 in the wash zone. With prior art washers, these pulp fibers float to the top of the vat and accumulate there. In time, a heavy wad may build up and plug the machine. The excluder baffle confines the fibers which have fallen off the mat to a small space and the washing action causes the pulp fibers to redeposit on the pulp mat.
  • Almost the whole circumference of the cylinder is sur­rounded by some kind of baffle. This leaves very little room for pulp to build up to a heavy wad and plug the machine. With both baffles in the open position, there is a divergent gap all around the cylinder to clear out any pulp.
  • The pulp mat 16 is again compacted by the secondary com­paction baffle to 12% to 15% consistency and then enters the take-off chamber 32. A take-off roll 54 assists in removing the pulp mat from the drum.
  • Referring to Fig. 4, the take-off roll 54 serves two functions: remove the pulp mat from the drum and convey the pulp longitudinally to the pulp outlet. The take-off roll shown in Fig. 4 includes a plurality of flutes 56 which are preferably arranged in a spiral pattern. A pressure zone 58 and suction zone 60 are created in the incoming and outgoing nip, respectively. This pressure and suction action will lift off the pulp mat from the cylinder. The lifted-off pulp mat is conveyed longitu­dinally by the spirally arranged flutes 56 in the take-­off roller 54. The conveying of the pulp suspension is also assisted by a pressure drop in the take-off chamber 32 towards the throttle valve 62 in pulp outlet 61 (see Fig. 1). A dilution liquid inlet 64 is provided at the opposite longitudinal end of the take-off chamber 32 from the pulp outlet 61 for feeding dilution liquid into the take-off chamber 32. Thus, the consistency of the pulp in take-off chamber 32 may be adjusted over a wide range by feeding a predetermined amount of dilution liquid into the take-off chamber 32 by means of the dilution liquid inlet 64.
  • Underneath the take-off roll 54 is a doctor 66 which can be operated with steam or water or with a combination of steam and water fed through manifold 67, port 69, and slot 71. The doctor removes any remaining crumbs of pulp and cleans the drum for the next cycle.
  • The pulp is fed to the vat 10 through pulp inlet 14. The pulp is formed and compacted into a pulp mat 16 by the first compaction baffle 18. As the drum 12 rotates, the mat goes through the wash zone 22 on the drum 12 and un­der the excluder baffle 30 and secondary compaction baf­fle 24. The secondary compaction baffle 24 converges to­ward the drum from its upstream end to the downstream end to again compact the mat 16. As the mat 16 enters the take-off chamber 32, the take-off roll 54 removes the mat from the drum 12 and the pulp thus removed is longitudin­ally conveyed through the flutes of the take-off roll 54 to the pulp outlet 62. If desired, the consistency of the pulp from the pulp outlet 62 may be controlled by feeding dilution liquid into the take-off chamber 32 through dilution liquid inlet 64.
  • Most of the parts shown in the embodiment of Fig. 2 are the same as corresponding parts in Fig. 1 except that in the embodiment of Fig. 2, a single wash liquid inlet 28 is used. Thus, the secondary wash liquid inlet 44 of the embodiment of Fig. 1 is eliminated. Referring to Fig. 2, a longitudinally extending pivot 80 extends through a plurality of longitudinally separated pairs of brackets 82 and 84 (only one pair shown in the Fig. 2). Brackets 82 are connected to the downstream end of excluder baffle 30; brackets 84 are connected to the upstream end of the secondary compaction baffle 24. Since the pairs of brackets 82 and 84 are longitudinally separated, an open­ing exists between each pair of brackets so that after the start-up and the vat has been completely filled with liquid, wash liquid entering wash liquid inlet 28 flows along the outside surface of primary compaction baffle 18 then along the outside and inside surfaces of excluder baffle 30 and then along the inside surface of the secon­dary compaction baffle 24.
  • The operation of the pulp washer of Fig. 2 is similar to the operation of the pulp washer of Fig. 1. Pulp enter­ing inlet 14 is compacted in the compaction zone by the primary compaction baffle 18 to form the mat 16. The mat 16 thereafter flows under the excluder baffle 30 and un­der the secondary compaction baffle 24 as it is washed in the wash zone of the drum. The secondary compaction baf­fle 24 again compacts the mat 16. In the take-off cham­ber 32, the mat is removed from the drum by the take-off roll 54 and longitudinally conveyed along the flutes of the take-off roll 54 to the pulp outlet 61 controlled by throttle valve 62. If desired, the consistency of the pulp from the take-off chamber 32 may be controlled by adding dilution liquid into the take-off chamber 32 through dilution liquid 64.
  • Most of the parts shown in the embodiment of Fig. 3 are the same as corresponding parts in the embodiment of Fig. 1 and the embodiment of Fig. 2.
  • Referring to Fig. 3, the first washing liquid inlet 90 extends into the vat 10 by means of a metal tube 92 having a portion 93 turned to extend toward the down­stream end of the vat. Metal portion 93 extends into one end of a rubber sleeve 94 which in turn surrounds the end of a tubular member 96 which is attached to a bracket 98 connected to the first compaction baffle 18. The bracket 98 is provided with an opening 100 through which the washing liquid entering the washing inlet 90 flows.
  • The washing liquid then flows along the inside surface of the excluder baffle 30 and along the inside surface of the secondary compaction baffle 24.
  • The downstream end of the primary compaction baffle 18 is pivotably connected to the upstream end of the excluder baffle 30 by means of a pivot pin 102 extending through bracket 104.
  • An actuator 106 applies a compaction force against the excluder baffle 30. Piston rod 108 extends from actuator 106 to the generally radially extending member 110. An arm 112 having a slot 114 is connected to the member 110 by pin 116. Bracket 118, connected to the excluder baf­fle 30 has a peg 120 which fits within slot 114 in the arm 112. The arm 112 is pivoted to vat 10 by pivot pin 122.
  • A second washing liquid inlet 123 extends into the vat 10 upstream from the first washing inlet 90. Liquid enter­ing the wash liquid inlet 123 flows along the outside of primary compaction baffle 18, then along the outside of the excluder baffle 30, and then along the inside of the secondary compaction baffle 24. The secondary compaction baffle 24 is provided at its upstream end with a bracket 124 which is pivotably connected by pivot pin 125 to bracket 126 extending from the wall of vat 10. The second washing liquid may be at a different temperature or concentration from the washing liquid fed through washing liquid inlet 90. Also, even though two washing liquid inlets are shown, more than two washing liquid inlets may be provided, if desired.
  • In the operation of the embodiment of Fig. 3, pulp enter­ing inlet 14 is compacted in the compaction zone by the primary compaction baffle 18 to form the mat 16. The mat 16 thereafter flows under the excluder baffle 30 and un­der the secondary compaction baffle 24 as it is washed in the wash zone of the drum. The secondary compaction baf­fle 24 again compacts the mat 16. In the take-off cham­ber 32, the mat is removed from the drum by the take-off roll 54 and longitudinally conveyed along the flutes of the take-off roll 54 to the pulp outlet 61 controlled by throttle valve 62. If desired, the consistency of the pulp in the take-off chamber 32 may be controlled by adding dilution liquid into the take-off chamber 32 through dilution liquid inlet 64.

Claims (8)

1. A pulp washer comprising: a rotatable drum (12); an air tight vat (10) completely enclosing the rotatable drum (12), said vat (10) being constructed so that the rotatable drum (12) may be completely submerged in liquid so that liquid surrounds the entire circumference of the drum, the vat having a liquid filled take-off chamber; a pulp inlet (14) to the vat; means (18) directly following the pulp inlet for forming and compacting the pulp to form a pulp mat (16); means (28) for washing the pulp mat directly following the means (18) for forming and compacting the pulp; means (24) for again compacting the pulp mat (16); characterized by means for controlling consistency of the pulp removed from said pulp washer including means (54, 58, 60) for removing the pulp mat from the drum and conveying it towards a pulp outlet (61), the removal point being located in the liquid filled take-off chamber (32) to provide a pulp suspension at said removal point in said chamber; and said pulp outlet (61) extending from the liquid filled take-off chamber.
2. A pulp washer in accordance with claim 1 further characterized in that the means for removing the pulp mat from the drum is a take-off roll (54) which removes the pulp mat (16) and conveys the pulp slurry to the pulp outlet (61).
3. A pulp washer in accordance with claim 2 further characterized in that the means for again compacting the pulp is a compaction baffle extending at least partially along the wash zone and into the liquid filled take-off chamber.
4. A pulp washer in accordance with claim 3 further characterized in that the means directly following the pulp inlet for forming and compacting the pulp to form a pulp mat comprises a compaction baffle (24).
5. A pulp washer in accordance with claim 4 further characterized in that the compaction baffle (24) extends along a drum forming zone and compacting zone, the means for washing the pulp mat on the drum comprises a drum wash zone extending circumferentially from the downstream end of the compaction baffle (18) to the liquid filled take-off chamber (32) and a washing liquid inlet (28,90) to the vat circumferentially located so that washing liquid flows along the outside of the compaction baffle, and then into the drum along the wash zone.
6. A pulp washer in accordance with claim 4 further characterized in that the compaction baffle (18) extends along a drum forming zone and compacting zone and the means for washing the pulp mat on the drum comprises a drum wash zone extending circumferentially from the downstream end of the compaction baffle (18) to the liquid filled take-off chamber (32), a coaxial baffle (30) extending from the compaction baffle partially along the wash zone, and connected to the compaction baffle (24) extending into the liquid filled take-off chamber (32), said compaction baffle (24) converging toward the drum from the coaxial baffle (30) to the liquid filled take off chamber (32), a washing liquid inlet (28, 90) to the vat circumferentially located so that washing liquid flows along the outside of the compaction baffle (18), the coaxial baffle (30), and the converging baffle (24) being constructed so that washing liquid also flows along the inside surface and outside surface of the coaxial baffle (30), and along the inside surface and outside surface of the converging baffle (24).
7. A pulp washer in accordance with claim 5 further characterized in that the means for washing the pulp mat on the drum also includes a second washing liquid inlet (44) to the vat located circumferentially at the coaxial baffle (30) - converging baffle (24) interconnection, the liquid fed to the second washing liquid inlet flowing along the inside surface and outside surface of the converging baffle (24).
8. A pulp washer in accordance with claim 7 further characterized in that the vat has a dilution inlet (64) for feeding dilution liquid into the take-off chamber (32).
EP89302748A 1988-03-21 1989-03-20 Pulp washer Expired - Lifetime EP0334583B1 (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
AT89302748T ATE86689T1 (en) 1988-03-21 1989-03-20 PULP WASHER.

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
US171045 1988-03-21
US07/171,045 US4827741A (en) 1988-03-21 1988-03-21 Pulp washer discharging a pulp slurry at a controlled consistency

Publications (3)

Publication Number Publication Date
EP0334583A2 true EP0334583A2 (en) 1989-09-27
EP0334583A3 EP0334583A3 (en) 1991-03-20
EP0334583B1 EP0334583B1 (en) 1993-03-10

Family

ID=22622263

Family Applications (1)

Application Number Title Priority Date Filing Date
EP89302748A Expired - Lifetime EP0334583B1 (en) 1988-03-21 1989-03-20 Pulp washer

Country Status (9)

Country Link
US (1) US4827741A (en)
EP (1) EP0334583B1 (en)
JP (1) JP2762294B2 (en)
AT (1) ATE86689T1 (en)
BR (1) BR8901281A (en)
CA (1) CA1308952C (en)
DE (1) DE68905207T2 (en)
ES (1) ES2039849T3 (en)
FI (1) FI92723C (en)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US7807060B2 (en) * 2004-07-09 2010-10-05 Bhs-Sonthofen Gmbh Filter with resuspension of solids

Families Citing this family (19)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5203968A (en) * 1988-04-13 1993-04-20 A. Ahlstrom Corporation Apparatus for treating fiber suspensions having rotatable liquid permeable treatment ducts
FI79867C (en) * 1988-04-13 1990-03-12 Ahlstroem Oy FOERFARANDE OCH ANORDNING FOER BEHANDLING AV FIBERSUSPENSIONER.
US5013460A (en) * 1989-11-13 1991-05-07 Kamyr, Inc. Centrifugal washer for paper pulp with means to feed pulp as a thin sheet
US5046338A (en) * 1990-06-13 1991-09-10 Ingersoll-Rand Company Multiphase pulp washer
FI88940C (en) * 1991-06-17 1993-07-26 Sunds Porin Tehtaat Oy DRUMTVAETTARE
US5213686A (en) * 1991-08-26 1993-05-25 Kamyr, Inc. Compression feeder
US5266168A (en) * 1991-12-20 1993-11-30 The Black Clawson Company Gravity type pulp washer or thickener with rotating disrupters
US5275024A (en) * 1992-05-04 1994-01-04 The Black Clawson Company Paper pulp washing
SE502815C2 (en) * 1994-05-03 1996-01-22 Kvaerner Pulping Tech Method and apparatus for treating a liquid fibrous material
SE503071C2 (en) * 1994-07-04 1996-03-18 Kvaerner Pulping Tech Continuous pulp wash diffuser including annular hydraulic cylinders
SE504471C2 (en) * 1995-06-12 1997-02-17 Kvaerner Pulping Tech Drum filter supported by carrier rolls for washing fiber material
US5722264A (en) * 1995-08-07 1998-03-03 Beloit Technologies, Inc. Single roll displacement wash press
CA2270382A1 (en) * 1998-05-05 1999-11-05 Ian James Henry Clarke-Pounder Totally submerged pressurized pulp washer and method of operation thereof
US6006554A (en) * 1998-06-03 1999-12-28 Beloit Technologies, Inc. Two stage counter current drum washer
SE0400940L (en) * 2004-04-07 2005-08-16 Kvaerner Pulping Tech Method and apparatus for diluting dewatered cellulose pulp
SE528722C2 (en) * 2005-06-03 2007-01-30 Metso Paper Inc Apparatus for treating cellulose pulp in a washing apparatus provided with a reinforcing sheath
US7976682B2 (en) * 2008-09-23 2011-07-12 Andritz Inc. Hinged screen plate for drum pulp washer and method for cleaning the plate
US8828189B2 (en) * 2012-01-30 2014-09-09 Andritz Inc. Washer press with multiple nips and multiple displacement wash zones
SE546043C2 (en) * 2021-09-24 2024-04-23 Valmet Oy Apparatus for washing cellulose pulp comprising a liquid distributor

Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3772144A (en) * 1971-04-14 1973-11-13 Improved Machinery Inc Apparatus and method for thickening and washing suspensions containing fibrous material
US4217170A (en) * 1977-11-18 1980-08-12 Ingersoll-Rand Company Pulp washer discharging a low consistency pulp slurry
US4292123A (en) * 1978-06-01 1981-09-29 Enso-Gutzeit Osakeytio Procedure and apparatus for cellulose washing

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3772144A (en) * 1971-04-14 1973-11-13 Improved Machinery Inc Apparatus and method for thickening and washing suspensions containing fibrous material
US4217170A (en) * 1977-11-18 1980-08-12 Ingersoll-Rand Company Pulp washer discharging a low consistency pulp slurry
US4292123A (en) * 1978-06-01 1981-09-29 Enso-Gutzeit Osakeytio Procedure and apparatus for cellulose washing

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US7807060B2 (en) * 2004-07-09 2010-10-05 Bhs-Sonthofen Gmbh Filter with resuspension of solids

Also Published As

Publication number Publication date
FI92723B (en) 1994-09-15
JPH01280089A (en) 1989-11-10
DE68905207T2 (en) 1993-06-17
DE68905207D1 (en) 1993-04-15
FI92723C (en) 1994-12-27
FI891312A (en) 1989-09-22
BR8901281A (en) 1989-11-07
EP0334583A3 (en) 1991-03-20
CA1308952C (en) 1992-10-20
FI891312A0 (en) 1989-03-20
JP2762294B2 (en) 1998-06-04
ATE86689T1 (en) 1993-03-15
EP0334583B1 (en) 1993-03-10
US4827741A (en) 1989-05-09
ES2039849T3 (en) 1993-10-01

Similar Documents

Publication Publication Date Title
EP0334583B1 (en) Pulp washer
US4085003A (en) Pressure pulp washer with pivoted baffle
WO1997005940A1 (en) Single roll displacement wash press
DE68928632T2 (en) Process and apparatus for treating pulp
NO175381B (en) Apparatus for continuous cooking of cellulosic fibrous material
US4538765A (en) Method for defiberizing waste paper in a thick stock range
GB2151509A (en) Apparatus for cleaning fibrous suspensions
US4217170A (en) Pulp washer discharging a low consistency pulp slurry
NO174782B (en) Method of backwashing a strainer in a pulping apparatus
EP0337432A2 (en) Method and apparatus for treating fiber suspensions
US4808265A (en) Method of washing pulp in a pressure pulp washer adding two washing liquids
US2802572A (en) Screen unit for treating solid matter of a suspension
WO1997013026A1 (en) Apparatus for dewatering/pressing in combination with washing of paper pulp
EP0547057B1 (en) Pressurized dynamic washer
CA2089076A1 (en) Method and apparatus for improving the treatment of a gas containing fiber suspension
WO1990010109A1 (en) Pulp washing apparatus and process
GB2128498A (en) A breaker
US6290067B1 (en) Screening apparatus with dilution liquid supply means
US4343708A (en) Method and equipment for thickening of suspension or pulp
DE69010128T2 (en) Method and device for emptying the pulp cooker.
US3681191A (en) Paper pulp digester blowdown method
US5192454A (en) Method for treating fiber suspension
CA2241540C (en) Pumping of medium consistency, high temperature pulps from stand pipes
WO2000075419A1 (en) Distribution device for a device for dewatering pulp
US5187956A (en) Preventing clogging in pressure diffusers

Legal Events

Date Code Title Description
PUAI Public reference made under article 153(3) epc to a published international application that has entered the european phase

Free format text: ORIGINAL CODE: 0009012

AK Designated contracting states

Kind code of ref document: A2

Designated state(s): AT DE ES FR GB IT SE

PUAL Search report despatched

Free format text: ORIGINAL CODE: 0009013

AK Designated contracting states

Kind code of ref document: A3

Designated state(s): AT DE ES FR GB IT SE

17P Request for examination filed

Effective date: 19910909

17Q First examination report despatched

Effective date: 19911220

GRAA (expected) grant

Free format text: ORIGINAL CODE: 0009210

AK Designated contracting states

Kind code of ref document: B1

Designated state(s): AT DE ES FR GB IT SE

REF Corresponds to:

Ref document number: 86689

Country of ref document: AT

Date of ref document: 19930315

Kind code of ref document: T

ITTA It: last paid annual fee
REF Corresponds to:

Ref document number: 68905207

Country of ref document: DE

Date of ref document: 19930415

ITF It: translation for a ep patent filed

Owner name: STUDIO ING. ALFREDO RAIMONDI

ET Fr: translation filed
REG Reference to a national code

Ref country code: ES

Ref legal event code: FG2A

Ref document number: 2039849

Country of ref document: ES

Kind code of ref document: T3

PLBE No opposition filed within time limit

Free format text: ORIGINAL CODE: 0009261

STAA Information on the status of an ep patent application or granted ep patent

Free format text: STATUS: NO OPPOSITION FILED WITHIN TIME LIMIT

26N No opposition filed
EAL Se: european patent in force in sweden

Ref document number: 89302748.2

PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: GB

Payment date: 19990212

Year of fee payment: 11

PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: FR

Payment date: 19990216

Year of fee payment: 11

PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: ES

Payment date: 19990318

Year of fee payment: 11

REG Reference to a national code

Ref country code: ES

Ref legal event code: PC2A

REG Reference to a national code

Ref country code: FR

Ref legal event code: TP

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: GB

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20000320

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: ES

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20000321

GBPC Gb: european patent ceased through non-payment of renewal fee

Effective date: 20000320

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: FR

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20001130

REG Reference to a national code

Ref country code: FR

Ref legal event code: ST

PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: AT

Payment date: 20010226

Year of fee payment: 13

PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: SE

Payment date: 20010305

Year of fee payment: 13

PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: DE

Payment date: 20010313

Year of fee payment: 13

REG Reference to a national code

Ref country code: ES

Ref legal event code: FD2A

Effective date: 20010910

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: AT

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20020320

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: SE

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20020321

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: DE

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20021001

EUG Se: european patent has lapsed

Ref document number: 89302748.2

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: IT

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES;WARNING: LAPSES OF ITALIAN PATENTS WITH EFFECTIVE DATE BEFORE 2007 MAY HAVE OCCURRED AT ANY TIME BEFORE 2007. THE CORRECT EFFECTIVE DATE MAY BE DIFFERENT FROM THE ONE RECORDED.

Effective date: 20050320